The present invention generally relates to a syringe having a connector for making a connection between the syringe and medical tubing.
Procedures involving the introduction of fluid into a patient's body often require that a syringe be connected through extension tubing to a catheter leading into a patient. One very specific procedure is angiography. Angiography involves introducing radiopaque substances into the blood stream of a patient to facilitate imaging of conditions within the vessels or arteries of the patient, for example, by X-ray equipment. Generally, a catheter is inserted into an appropriate blood vessel for imaging and the other end of the catheter is attached to extension tubing leading to a syringe containing the radiopaque liquid. A connector is required between the extension tubing and the discharge opening of the syringe. This connector should allow connection and disconnection between the end of the syringe and the end of the extension tubing. Not only must the connector facilitate ready connection and disconnection, but it must also be capable of withstanding the high pressures exerted by angiographic injector when the injector is activated to force the radiopaque liquid into the extension tubing and catheter.
Various configurations of syringe discharge ends, connectors and tubing ends have been used to facilitate the connection between the tubing and the syringe. Often, these connections have involved twisting the tubing end onto the syringe discharge end to thereby tighten the connection between respective male and female luer tapers on the syringe discharge end and on the end of the tubing. Another type of connection system is shown, for example, in U.S. Pat. No. 4,573,978 (the '978 patent). This system utilizes an intermediate rotatable connector having internal, oppositely facing tabs at one end and an internally threaded section at the opposite end. The connector also includes intermediate windows or sections void of material. The syringe discharge end includes a tapered section and a circumferential track or recess. The connector is attached to the syringe discharge end by pushing the connector onto the discharge end allowing the tabs to ride up and over the tapered section and then snap into place within the track or recess. The windows allow the connector to have the resilience necessary for the tabs to move away from each other and then snap into the recess. The connector is then held rotatably within the recess and a connection between the syringe discharge end and the tubing end may be made by rotating the connector and threading it onto a suitably formed end of the tubing.
The various connection systems employed in the past for syringes and, more specifically, for angiographic injection systems, each have their own set of disadvantages or problems. Most notably, with respect to the systems requiring that the tubing be twisted relative to the syringe to make the connection, the twisting action to make the connection can be bothersome and inconvenient, since the tubing is often already connected to the patient, and thus it is preferable not to twist the tubing, and in addition, the syringe is typically already locked into an injector apparatus, and thus not rotatable, when the tubing is attached.
The connection system disclosed in the '978 patent has disadvantages associated with the spring locking tabs and windows required in the intermediate connector member. Specifically, the necessary deformation of the connector during the assembly process may weaken the connector and make it more likely to fail. Additionally, the resilience or weakening of the connector may make it more likely to be forced off the syringe discharge end under pressure. Finally, snap fit parts, such as the connector member in the '978 patent, may require manufacturing tolerances which unacceptably increase manufacturing costs.
It would therefore be desirable to provide a connection system for connecting a syringe discharge end to tubing which not only is easy to manufacture, but which is also easy to use by the technical personnel in the field and which is reliable when used uses in high pressure systems, such as angiographic injector systems.